Alarm wristwatch

ABSTRACT

1,172,546. Alarm watches. P. SPADINI. Feb.17, 1967 [Feb.17, 1966; June 8, 1966; Sept.9, 1966], No.7756/67. Heading G3T. An alarm wrist watch comprises a membrane 17 for generating an audible alarm, a spring blade 18 capable of vibrating at a predetermined natural frequency and positioned to cause the membrane to vibrate, and electrical control means for maintaining the vibration of the spring blade, the electrical control means being actuated by a switch which is operated at a predetermined time by the watch movement. The spring blade 18 is rigidly secured to a post 19 and carries an armature 20 which co-operates with the electrical control means comprising a permanent magnet and coils connected to a conventional battery driven transistorized circuit. An alarm hand is set by rotating a bezel 3 which carries the watch glass 2 and at the pre-set time the alarm sound is transmitted through openings 16 which may be partially or completely closed by a shutter to limit the intensity of the sound. A push button switch is provided in series with the movement actuated switch to enable the alarm to be shut off. The watch case is rectangular but modifications are described for circular watch cases and the alarm sound may be produced by the blade striking a pin attached to the watch glass. In a further modification, the alarm mechanism comprises a timing fork with circular tines, one of which is adapted to strike a bell and a tuning fork with parallel tines may also be used.

Aug 26, 1969 P. A. sPADlNl ETAL ALARM WRISTWATCH 3 Sheets-Sheet l FiledFeb. 13, 1967 EJE. 2

EYE. Z

Aug. 266, 1969 P. A. sPADlNl ETAL ALARM WR I STWATCH I5 Sheets-Sheet 2Filed Feb. 13, 1967 US- 26, 1969 l P. A. sPADxNl ETAL. 3,462,943

ALARM WRISTWATCH a Filed Feb. 13, 1967 -3 Sheets-Sheet 3 United StatesPatent O 3,462,943 ALARM WRISTWATCH Paolo A. Spadini, 88 Ave.Leopold-Robert, La Chaux-de- Fonds, Switzerland, and Andre Micheloud,Bern, Switzerland; said Michelond assignor to said Spadini Filed Feb.13, 1967, Ser. No. 615,495 Clalms priority, application Switzerland,Feb. 17, 1966, 2,306/ 66; June 8, 1966, 8,252/66; Sept. 9, 1966,

Int. Cl. G04b 23/12 U.S. Cl. 58-57.S 16 Claims ABSTRACT OF THEDISCLOSURE BACKGROUND OF THE INVENTION Field of the invention Theinvention relates to alarm Wristwatches of a particular well known type.The type of alarm Wristwatches referred to here may be specified bythree particulars:

(l) The audible sound of the alarm device is produced by a generatorprovided in the form of a vibrating member;

(2) An actuating device, which is operable by means of a source ofenergy, is arranged so that it can set the sound generator intovibration;

(3) A releasing mechanism is associated with both said actuating deviceand the watch movement. This releasing mechanism has a locking positionin which it keeps inoperative the actuating device, thus holding thealarm device at rest. As regards the association of the releasingmechanism with the watch movement, it is conceived in such a way thatthe watch movement may remove the releasing mechanism from its lockingposition at predetermined hours. As soon as the releasing mechanism hasbeen removed from its locking position, the actuating device becomesoperative and consequently the sound generator produces an audiblesound.

Description of the prior art The alarm Wristwatches which can be foundon the market are provided with a mechanical alarm device. This deviceusually comprises a hammer provided for striking on the vibrating soundgenerator. The hammer carries an escapement lever which is actuated byan escape wheel. The source of energy used for -driving the alarm deviceof these known Watches consists of a spring motor housed in a barrelwhich is connected to the escape wheel by gear means. The member againstwhich the alarm hammer strikes is either the sound generator itself or apin secured thereto. In the trst event, the sound generator is usuallyconstituted by a bell secured to the Watchcase bottom While in thesecond one, it is either the bottom itself or a metallic membranesecured to the caseband and forming part of a double bottom.

Most of these known watches are provided with two control stems, one forWinding up the watch and for setting the hands thereof, and the otherone for winding up the alarm device and for setting the time of thealarm. There are also alarm Wristwatches provided with "ice a singlecontrol stem. When this stem is in Winding positlon, rotating the samein one direction winds up the watch and rotating the stem in the opposeddirection winds up the alarm device. By shifting the stem into differentaxial positions, one can set the watch hands and the alarm hand.

Alarm Wristwatches comprising a single spring motor for driving both thewatch movement and the alarm device are also known in the art. A lockingdevice is provided for preventing this spring motor from dissipating allthe energy stored up therein, when the alarm is released. The additionalmechanisms which have to be provided 1n the alarm Wristwatchescomprising either a single control stem or a single spring motor arequite particular and delicate. Moreover, they do not operate safely. Inaddition thereto, these mechanisms can hardly be mounted in a standardwatch movement which had originally been designed for other purposes, sothat a particular watch movement has to be designed and manufacturedespecially in view of the alarm device which will have to beincorporated therein.

Besides the drawbacks, which are specically due to these particularmechanisms, the known alarm Wristwatches provided with a mechanicalalarm device have all the same drawback. Due to the fact that the watchmovement has to be provided with a hammer which is able to strikeagainst a member secured to the watchcase bottom, such a mechanical`alarm device can hardly be incorporated with a watch movement providedwith a conventional selfwinding device. A conventional selfwinding Watchindeed comprises a Winding weight which is journalled in the center ofthe movement and which comprises a heavy portion moving all round themovement and this winding weight thus constitutes a barrier between themovement and the Watchcase bottom, which cannot be crossed by anyelement (pin or stud) fixed to the bottom and against which the hammercould strike. On the other hand, a winding Weight which only oscillateswithin a sector limited by stops does notoriously not operate in anadequate manner.

Finally, even if the watch movement were wound up automatically by meansof a small winding weight mounted in an eccentric position Within thewatch movement, the alarm wristwatch equipped with a mechanical alarmdevice would still have the drawback that it would not be a fullyselfwinding watch. Everytime after the alarm device has run down, onewould have to wind it up by hand in order to set it again.

As a matter of fact, there are also timepieces in which winding up thespring motor of the alarm device occurs electrically, by means of amotor. The operation of such a motor, however, requires a powerfulsource of energy. If a motor were provided for winding up the alarmdevice of a wristwatch, this motor should accordingly be supplied withcurrent from a battery which could not possibly be mounted in the casingof a wristwatch. There are truly also timepieces with an alarm device inwhich the hammer striking the sound generator is also actuated by asource of electric current, but in a more economic manner. Instead ofactuating the hammer mechanically by means of an escape wheel driven bya spring motor and of a lever secured onto the hammer shaft, the hammeris actuated electromagnetically, by means of a fixed coil which isperiodically energized and of a permanent magnet fixed onto the hammershaft.

The hammers of these known alarm devices have, however, a relativelygreat inertia so that they can only be actuated by a correspondinglypowerful source of energy. iIn other words, these known alarm deviceshave still too small a yield for their efficient accommodation withinthe sizes of a wristwatch. The required source of energy could notpractically be located in the watchcase.

Summing up, among the known alarm devices there is no small one whichcould be associated with a conventional selfwinding wristwatch and thereis neither one which could be associated with a selfwinding `watchmovement and simultaneously be reduced to such sizes as to be suitablefor the accommodation of all its components within the boundaries of thecasing of a wristwatch.

SUMMARY OF THE INVENTION The alarm wristwatch according to the inventionis improved by a new alarm device. This alarm device sets the soundgenerating member into vibration by means of an armature which isarranged for vibrating itself at a natural frequency substantially equaltothat of the audible sound which said sound generating member isintended to produce. Moreover, said armature is kept vibrating at saidnatural frequency by means of a controlling electromagnetic eld which issupplied by an electric source of energy.

Since the armature of the alarm device according to the invention isarranged so as to vibrate at a natural frequency, keeping this armaturevibrating at said frequency does obviously not dissipate a great amountof energy. The alarm device of the alarm wristwatch according to theinvention has thus a substantially higher yield than the alarm devicesof the known watches. It is therefore possible without any difficulty toactuate said alarm device by means of a battery having the adequatesizes for accommodating the same within the casing of a wristwatch.

The sound generating member can consist of a plastic membrane which iscapable to vibrate at different frequencies of the audible spectrum. Ina watertight wristwatch the use of another type of sound generatingmember, for instance of a member which can itself vibrate at a naturalfrequency, will simplify the construction. With such a sound generatingmember the armature of the alarm device according to the invention willadvantageously cause this sound generating member to vibrate by strikingthereon. Said sound generating member can thereby consist of either thewatchcase bottom, or a bell secured to this bottom, or a metallicmembrane forming part of a double bottom and accordingly having itsperiphery secured to the caseband. The sound generating member can evenconsist of the watch glass. To set the same into vibration, the armatureof the alarm device can strike for instance against a pin secured to theglass and extending through a dial opening.

As regards the armature itself of the alarm device according to theinvention, it can either be carried by a spring blade having one endrigidly fixed to a support, or consist of such a spring blade, or evenconsist of one branch of a tuning fork.

In addition to the fact that entertaining the vibration of a tuning forkat its natural frequency ensures a very high yield, and to the fact thatusing a tuning fork for striking on a membrane or a bell only dissipatessmall amounts of energy, the tuning fork has still a particularadvantage. It can be made in a shape which will be particularly suitablefor accommodating the same within the casing of a wristwatch. A tuningfork can indeed be made with a shape similar t`o that of the watchmovement so that it `will be possible to locate the same within theannular space which is usually comprised between the watch movement andthe casing. However, the tuning fork can of course also be made withparallel branches and be mounted within the `watch movement itself, forinstance at the place provided in the conventional movements forlocating the mechanical alarm devices used heretofore.

to the invention are represented diagrammatically and by way of examplein the drawing in which:

FIG. l is a plan view of the first embodiment;

FIG. 2 is a view similar to that of FIG. 1, the casing being open andsome parts having been removed;

FIG. 3 is a part sectional view on a larger scale along line III-III ofFIG. 1;

FIG. 4 is a diagram of the electrical connections included by the alarmdevice of the watch;

FIG. 5 is a plan view of the second embodiment;

FIG. 6 is an elevational view with some parts in section of the thirdembodiment;

FIG. 7 is a partial plan view of this third embodiment, and

FIG. 8 is a plan view of the fourth embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The watch represented in FIGS.1 through 4 is a rectangular wristwatch. It is provided with a circularwatch movement (not shown) which comprises a selfwinding mechanism ofconventional type. To release the alarm device, this 4watch movementcomprises a cam and a movable contact member cooperating with said cam,both being mounted onto the motion work of the movement coaxiallythereto, substantially as disclosed in the Swiss Patent No. 371,750.Like in that patent, the alarm hand 1 can be set by rotating the glass 2which is carried by a rotatory Ibezel 3. The watch movement is locatedin a lodging 4 of a frame member 5 which is furthermore provided withthe additional lodgings 6, 7 and 8 for the accommodation of thedifferent units of the alarm device. The frame member 5 has an outershape matching with the side wall of a watchcase piece 9 whichconstitutes both the watchcase bottom and the case band and whichcarries the lugs 10 to which the Wristband 11 is attached. Aconventional crown 12 enables both manually winding up the watchmovement and setting the watch hands 13.

A cover member 14 is removably secured to piece 9 and closes thewatchcase. The cover member 14 carries an annular projection 1S servingas journalling means for the rotatory bezel 3. Cover member 14 isprovided with a series of openings 16 in order to ensure the passage ofthe sound produced by the alarm device as described hereinafter. Dustis, however, prevented from entering the watchcase by means of amembrane 17 which is secured to the cover member 14 under the openings16.

The membrane 17 constitutes the sound generating member of a soundgenerator of the type disclosed in Swiss `Patent No. 409,715. Membrane17 can be set into vibration by means of a spring blade 18, which isrigidly secured at one end to a stud 19 xed itself to cover member 14.For this purpose the spring blade 18 carries an armature 20 whichextends over a permanent magnet being in the form of a magnetic sleeve21. A stimulating coil and a motor coil (not shown) are mounted withinsleeve 21. These two coils are connected to a transistorized well knowncontrol circuit (not shown), which is supplied by a battery 22 lying inlodging 8 of frame member 5. The stimulating coil is sensitive to thevariations of the magnetic flux between sleeve 21 and armature 20, whichoccur when blade 18 vibrates. This stimulating coil biases then thecontrol circuit periodically at a frequency equal to the naturalfrequency of blade 18 and in such manner that the motor coil givesentertaining impulses to blade 18 through armature 20 at moments whichhave the adequate difference of .phase in order to produce a phenomenonof resonance and to entertain in that way a strong vibration of blade18. In the absence of membrane 17, blade 18 would vibrate at arelatively low natural basis frequency. Membrane 17, which has apyramidally shaped central portion is, however, located in the vicinityof blade 18 so that the apex of the pyramidal portion of membrane 17lies opposite a predetermined point of blade 18. This point iscalculated according to the theory of vibrations in such manner thatblade 18 will not transmit its basis vibration to membrane 17 but a goodaudible harmonic thereof, which has a substantially higher frequency.For that purpose the apex of the pyramidal portion of membrane 17 canalways remain in contact with blade 18, for instance by means of a rigidconnection such as provided by welding, gluing, riveting, or simply bypressure. Similar results can, however, also be obtained if blade 18strikes against the apex of membrane 17. By vibrating over lodging 7,which operates as a sound box, membrane 17 generates a relatively puresound Awhich is perfectly audible.

Tests have shown that a membrane having an area of about 150 mm.2 can bekept vibrating by a current of 5 ma. at a frequency of 4000 cycles persecond and produce a sound having still an intensity of 70 to 80 phon ata distance of 30 cm. With a source of energy constituted by one of thesmallest available batteries, it has been possible to hold the alarmdevice 4of the watch described ringing uninterruptedly during 45 hours.

A pushbutton 23 actuates a switch 24 located in lodging 6 of framemember 5 and permits stopping the alarm device from outside the casingat any desired moment.

The different units of the alarm device are electrically connected asshown in FIG. 4. The sound generator 25 comprising blade 18 and membrane17 is connected in the circuit supplied by battery 22 in series withswitch 24 and a contact 26. Contact 26 is actuated by cam 27 of thereleasing mechanism of the alarm device, which is mounted coaxially tothe motion work of the watch as indicated hereabove.

In the manufacture of the watch represented in FIGS. l through 4 anyavailable conventional watch movement either circular or of anothershape can be used. The releasing mechanism of the alarm device need onlybe mounted thereon.

Since the alarm device of the watch described produces a relatively puresound, the intensity of that sound can easily be varied at vwill withinbroad limits. For that purpose, a shiftable shutter provided underopenings 16 for closing these openings to a more or less great extent,constitutes a suitable means. If the alarm device has to be set so thatit will be released at a time at which the Watch carrier is for instancein conference, the openings 16 can be closed and the sound intensityaccordingly reduced to such an extent that only the watch carrier willbe able to hear the alarm device of his watch.

In order to avoid that foreign particles fall onto membrane 17 throughopenings 16 and gradually prevent that membrane from vibrating properly,a sheet of soft material could be stretched under openings 16.

Since membrane 17 can anyway be tightly fixed to cover member 14, thecasing of the wristwatch described can be made watertight without anydifculty.

The second embodiment (FIG. 5) is constituted by an alarm wristwatchhaving a circular shape. This watch comprises `a watch movement 28similar to that of the first embodiment. The different unitsconstituting the alarm device (battery 22a, magnetic sleeve 21a, blade18a, printed circuit 29 controlling the coils which actuate the soundgenerating member) are located around the watch movement 28, withinlodgings provided in an enlargement and engaging ring of the watchmovement. In this embodiment the watchcase opening for the sound of thealarm device is advantageously provided in the bottom of casing 30. Likein the first embodiment, the membrane constituting the sound generatingmember can be secured to the watchcase bottom so Vas to provide for atight closure of this casing. The watch of this embodiment can beprovided with `a conventional dial which extends over the whole visiblesurface of the watch. Hands 1a and 13a having sizes matching with thoseof the dial can also be provided.

Like in the first embodiment, the movement 28 can be wound up and thehands 13a can be set by means of a conventional crown 12, whereas thealarm hand 1a can be set by means of .a rotatory bezel 3a.

The manufacture of a watertight alarm wristwatch can, however, beperformed easier as shown by the third embodiment (FIGS. 6 and 7).

In this embodiment the watchcase has again a rectangular or square shapeand the glass 31 comprises a peripheral flange 32, which is clamped inaxial direction between the upper edge of a piece 33 and an inwardsprojecting ange of a piece 34. Piece 33 constitutes the watchcase bottomand it comprises an upright wall surrounding the space provided for thewatch movement. Piece 34 is secured in a known manner to piece 33 and itconstitutes both the bezel .and the case band of the watchcase.

The alarm device of this watch also comprises -a magnetic sleeve 35.This sleeve is fixed to a bracket 36 which is located in an openingprovided in a frame member. Instead of positioning sleeve 35 so that itsaxis is parallel to that of the watch, like in the two firstembodiments, sleeve 35 is here, however, lying. A spring blade 37carrying an armature or constituting itself an armature has one endrigidly secured to bracket 36 by means of a rivet 38. The actuatingmeans provided for setting blade 37 into vibration are similar to thoseused in the two first ernbodiments.

The watch represented in FIGS. 6 and 7 still comprises a memberconnecting blade 37 to glass 31 in order to transmit the vibration 'ofblade 37 to the glass, which constitutes the sound generating member ofthis embodiment. This connecting member consists of a pin 39 having oneend embedded in a projection 40 of the glass. Pin 39 extends through anopening 41 of dial 42 so that its free end lies in the immediatevicinity of blade 37.

The vibration of blade 37 is transmitted to the glass 31 through pin 39preferably by striking. The glass produces thus an audible sound as longas its vibration is entertained by the coils located in sleeve 35, whichbias the controlling electromagnetic field.

Blade 37 carries a stud 43 which butts against a rigid part carried bybracket 36, when blade 37 is vibrating. As a consequence thereof, thebasis vibration of blade 37 has a wav-e length which is not four times,but only twice as long as blade 37. Moreover, the striking point ofblade 37 against pin 39 is chosen in such manner along blade 37, thatthe same vibrates at a natural frequency which is a harmonic of itsbasis frequency.

Pin 39 can be hidden by means of an ornamental design provided either onthe dial 42 or on a part of the lower surface of glass 31.

The watch of the fourth embodiment (FIG. 8) comprises a circular casing51 and a circular movement 52 which has a diameter somewhat smaller thanthat of lodging 53 of casing 51. A tuning fork 54 having the shape of.an open ring, is secured to movement 52 by means of a strap 55 whichseparates the two branches of the tuning fork from each other.

The vibration of tuning fork 54 is entertained in the same manner asthat of the blades described in the three first embodiments, namely bymeans of an electric control circuit comprising two coils 56, astimulating and a rnotor coil, which are carried by one branch of tuningfork 54 and which are connected in the input and in the output circuit,respectively, of a transistorized amplifier (not shown). Coils 56cooperate with a permanent magnet 57 carried -by the other branch of thetuning fork. The electrical control circuit of tuning fork 54furthermore comprises a first switch (not shown), which is mounted onthe hour wheel of the watch and a second manually operable switch forstopping the alarm at will. This second switch can be controlled fromoutside the casing by means of a pusher (not shown) carried by casing51.

When tuning fork 54 vibrates, a finger 58 carried by one of its branchesstrikes against the bell 59 which is secured to the watchcase bottom ina manner Well known to those skilled in the art. One 'branch of thetuning fork could also strike against a pin or a stud carried either bythe watchcase bottom or by a metallic membrane constituting a doublebottom of the watchcase.

The vibration of tuning fork 54 can be entertained with a substantiallysmaller dissipation of energy than the usual alarm hammer of the knownalarm watches. The small batteries, which are available on the marketand which are used in the known electric Wristwatches provided eitherwith a driving balance-wheel or with a regulating and driving tuningfork, can operate the alarm device of the watch represented in FIG. 8 atleast during a year, if the alarm is used on an average during fiveminutes every day.

In a shaped watch provided with a shaped movement the tuning fork usedas alarm hammer could also be made in a shape similar to those of thewatchcase and the movement, so that the tuning fork could be arrangedaround this movement. The tuning fork could, however, also be made withtwo parallel branches and be located at the side of the movement.Finally, the tuning fork could also be shaped so that it could bemounted in the movement itself, for instance at a place which wouldoriginally have been provided for a conventional mechanical alarmdevice.

Although different embodiments of the alarm wristwatch according to theinvention have been described in detail hereabove, it should beunderstood that various changes in the shape, sizes and arrangement ofparts will appear obvious to those skilled in the art.

What is claimed is:

1. An acoustical alarm device comprising mechanical sound generatingmeans, a resilient member having a natural frequency, and transstorizedelectromagnetical means arranged for causing said resilient member tovibrate at said natural frequency as soon as the transistorizedelectromagnetical means are energized and for entertaining the vibrationof said resilient member at said natural frequency as long as saidtransistor-ized electromagnetical means remain energized, said resilientmember being mechanically coupled to said mechanical sound generatingmeans for transmitting its vibration thereto.

2. The alarm device of claim 1, in which the mechanical sound generatingmeans consists of a vibrating member, said resilient member setting saidvibrating member into vibration by striking thereagainst.

3. The alarm device of claim 1, in which a spring blade having one endrigidly anchored forms part of said resilient member.

4. The alarm device of claim 1, in which a spring member is constitutedby a branch of a tuning fork.

5. The alarm device of claim 1, in which said electromagnetical meanscomprises an electrical amplier supplied by an electric source ofenergy, said resilient member reacting on said amplifier and causing thesame to entertain the vibration of the resilient member at said naturalfrequency.

6. The alarm device of claim 5, in which said electrical amplifiercomprises an input circuit including a stimulating coil sensitive to thevibration of said resilient member at its natural frequency and anoutput circuit including a motor coil imparting impulses t saidresilient member for entertaining its vibration at said naturalfrequency.

7. The alarm device of claim 6, in which said resilient member isconstituted by a tuning fork, one branch of said tuning fork carryingsaid stimulating and said motor coil, and the other branch of saidtuning fork carrying a permanent magnet cooperating with said coils.

8. An alarm wristwatch comprising a lirst member capable of generatingan audible alarm sound by vibrating, a second member capable ofvibrating at a predetermined natural frequency ranging within theaudible spectrum and being mechanically coupled to said first member fortransmitting its vibration thereto, thus generating an audible alarmsound as soon as said second member vibrates, and electrical controlmeans arranged for entertaining the vibration of `said second member atsaid predetermined natural frequency upon energization of saidelectrical control means, said electrical control means including aswitch being normally open and interrupting the energization of saidelectrical control means, said switch being set under the control of thewatch movement for being closed thereby at predetermined hours.

9. The wristwatch of claim 8, in which said first member includes thewatchcase bottom.

10. The wristwatch of claim 8, in which said rst member includes ametallic membrane having its periphery anchored to the case band andforming part of a double bottom.

11. The wristwatch of claim 8, in which said first member includes thewatch glass, a pin being fixed to said glass and extending through adial opening, `and said second member striking against said pin.

12. The wristwatch of claim 8, in which a tuning fork forms part of saidsecond member, said tuning fork having a shape similar to that of thewatch movement and being located in an annular space provided around thewatch movement, between the same and the watchcase.

13. The wristwatch of claim 8, in which a tuning fork forms part of saidsecond member, said tuning fork being mounted within the watch movement.

14. The wristwatch of claim 8, in which said first member includes aplastic membrane capable of vibrating at different frequencies of theaudible spectrum.

15. The wristwatch of claim 14, in which the casing thereof is providedwith an opening, said membrane having its periphery tightly secured to awatchcase portion surrounding said opening so as to obture the latter.

16. The wristwatch of claim 14, in which said second member permanentlyremains in Contact with said rst member and vibrates in unisontherewith, when said electrical control means are energized.

References Cited UNITED STATES PATENTS 1,529,852 3/1925 Tanglin 58-57.52,435,996 2/1948 Baird. 2,867,795 l/1959 Longton et al. 340-261 XFOREIGN PATENTS 375,664 11/ 1963 Switzerland.

RICHARD B. WILKINSON, Primary Examiner G. H. MILLER, JR., AssistantExaminer U.S. Cl. 340-261

